i) Field of the Invention
The present invention relates to polysulfide compounds and a lipid peroxidation inhibitor containing the polysulfide compounds as an active ingredient.
ii) Description of the Background Art
It is well known that a variety of vital phenomena involve a lipid peroxidation reaction, which is initiated by a free radical reaction. In particular, if the chain reaction of free radical is not cut off, an oxygen radical, a so-called active oxygen produced in any creature induces lipid peroxidation against lipids present as a basic material of a vital organism, for example, against polyvalent fatty acids constituting a matrix of a biomembrane.
That is, a lipid free radical and a peroxy free radical are produced in a series of steps to form a harmful peroxide lipid against the vital organism.
Hence, the lipid peroxidation reaction is concerned in a number of sicknesses or diseases, for instance, hemolytic anemia, various inflammations, myocardial infarction, cirrhosis of the liver, atherosclerosis and so forth, and further it is considered that this reaction participates in carcinogenesis and aging.
Thus, for preventing and curing sicknesses and diseases due to such lipid peroxidation, development of drugs or pharmaceuticals for inhibiting the lipid peroxidation have been demanded. Some drugs for inhibiting the lipid peroxidation have been proposed, but cannot necessarily have sufficient effectiveness.
Under the above circumstances, the present inventors have carried out research for developing drugs or pharmaceuticals having a clinically excellent lipid peroxidation inhibiting effect and have found that a group of polysulfide compounds having a formula (I): EQU R.sup.1 --(S).sub.m --R.sup.2 (I)
wherein R.sup.1 and R.sup.2 are same or different hydrocarbon chains having 1 to 16 carbon atoms and m is an integer of 3 to 10, which are obtained by an extraction from the Allium plants widely used as foods and drugs or pharmaceutical materials particularly garlic, scallion, elephant garlic or the like or a treated material thereof or by a chemical synthesis, possess an excellent lipid peroxidation inhibiting effect, and that a second group of polysulfide compounds included in the first group of the polysulfide compounds, having a formula (II): EQU R.sup.3 --(S).sub.n --R.sup.4 (II)
wherein R.sup.3 and R.sup.4 are same or different lower alkenyl groups and n is an integer of 6 to 10, are novel compounds.